Arsenal's biggest shareholder Stan Kroenke moved within 17 shares of the threshold that would force him into making a takeover bid for the club yesterday.

The American tycoon has bought up another 25 shares inside the past week and, although his stake in Arsenal remains at 29.9 per cent, he is edging ever closer to the 30 per cent holding that requires him to make a formal takeover bid and offer to buy the entire stockholding. The latest share acquisition is reported to have cost Kroenke around £212,500 and he has gradually increased his stake in Arsenal this year.

Arsenal's other main shareholders are the Uzbek businessman Alisher Usmanov, who holds a stake of around 25 per cent, diamond dealer Danny Fiszman, and Lady Bracewell-Smith.

Kroenke, who is based in Denver, also owns the NBA's Denver Nuggets basketball side and the Colorado Rapids MLS football team. At Arsenal's annual general meeting at the Emirates Stadium in October, Kroenke was asked about his intentions for the London club but he chose not to speak to the gathered shareholders, with the chairman Peter Hill-Wood intervening.

Hill-Wood pointed out that under takeover rules any public statements regarding future bid intentions must be unambiguous, otherwise the individual concerned would be prevented from making a formal takeover move for six months.

Once someone reaches a 30 per cent shareholding in a company they are deemed by the Takeover Panel to have "effective control" of it and must then make an offer for the remaining shares. The price offered cannot be lower than the highest price the potential buyer has paid for shares in the company in the previous 12 months.

If, after the offer has been made, the potential buyer has more than 50 per cent of the shares they are deemed to have succeeded in their takeover and be legally in control. If an offer is unsuccessful and the 50 per cent shareholding level is not breached the potential buyer cannot return with another takeover bid for 12 months, unless invited to do so by the company.

Lady Nina Bracewell-Smith, who left the board in December last year, could well hold the balance of power with her family's 15.9 per cent stake.